The subject invention relates to the art of furnace filters, and more particularly to furnace filter assemblies that include a continuous length of advanceable filter media instead of individual replacement filter cartridges.
Furnace filter assemblies have been provided heretofore, and generally, as shown in Koushiafes for example, have a filter frame which can be installed on an existing furnace in place of the standard filter cartridges normally installed thereon. Such assemblies include a roll of filter material that is adjacent one end of the filter frame and which extends through the frame to the opposite end. As can be best seen in FIGS. 1 and 2 of Koushiafes, the opposite end of the filter frame includes a knife edge which is used to remove filter material that has been manually pulled through the filter frame. Furnace filter assemblies such as that in Koushiafes require a person to install the filter frame on the furnace, thread the filter material through the frame, and then continually monitor the condition of the filter material by removing the entire filter frame from the furnace and visually inspecting it. Based on these repeated visual inspections, it will eventually be determined that the filter material is dirty and clogged, and therefore needs to be replaced. To advance the filter material, it must be grasped by hand, pulled out of the frame exposing a new length of filter material, and pulled against the knife edge to tear or cut the used filter material away from the newly exposed filter material now extending across the filter frame. Such requirements create a variety of problems and difficulties. First, the filter material in Koushiafes must be repeatedly monitored the same way a traditional filter cartridge must be, to insure efficient and effective operation. As previously indicated such monitoring requires that the filter frame be removed from the furnace, visually inspected for dirt and clogging, and then replaced. This is a dirty and time-consuming process which, furthermore, is subjective. As such, the filter material may be advanced before it has become inefficient and ineffective thereby wasting filter material, or oppositely, the filter material may be advanced only after it has long become ineffective. Second, the process of advancing the filter material by hand, tearing it across the knife edge on the frame, and discarding it, is a dirty job which will cause dirt collected in the used filter material to be deposited on the hand or hands of the user, to be dislodged and fall onto the floor where it must be cleaned up or to fall onto the users clothing which thus becomes soiled.
Furthermore, devices such as the one disclosed in Strong create a different set of problems and difficulties. The device in Strong eliminates some of the monitoring and handling requirements of Koushiafes, by providing a cleaning apparatus which removes dirt and contaminants from an endless belt of filter material. However, the device in Strong is not easily installed on an existing furnace. There are a significant number of individual components that must be properly installed and aligned. This may require extensive modification to the furnace and can be further complicated by limited clearance in the area around the furnace and its attendant duct work. Accordingly, the device in Strong would be difficult to properly install and thus is both time-consuming and expensive.
Finally, devices such as the one disclosed in the co-pending application of Najm have many advantages. However, such devices include a significant number of individual components each requiring alignment and installation. In fact, a device in accordance with Najm has a filter frame inserted into the interior of a duct and secured in place by fasteners. The filter frame fits into the duct through opposing slots that, most often, have to be cut into the duct work by the installer. Once the slots are cut and the filter frame inserted and fastened into place, a top and a bottom roller support has to be individually installed on the exterior of the duct with one each of the top and the bottom supports being adjacent each slot. The top and bottom supports must be carefully aligned with one another to rotatably support a filter cartridge therebetween. The filter cartridges are adapted to store and to receive a bulk roll of filter media, and must rotate freely between the top and bottom supports on each side of the duct to function without tearing the filter media extending between the cartridges. It will be appreciated that such a system may provide many advantages, but that such a system is also very difficult and time-consuming to install and, accordingly, undesirably expensive.
In accordance with the present invention, a furnace filter assembly is provided for installation on an existing furnace which avoids or minimizes the problems and difficulties encountered with devices of the foregoing character, while promoting and maintaining the desired simplicity of structure, economy of manufacture, and ease and thus economy of installation and operation. More particularly in this respect, a furnace filter according to the invention includes a filter frame that can be quickly and easily removably mounted on an existing furnace for supporting a supply roll used to store an unused filter media that is rotatably mounted on the filter frame, a take-up roll for receiving used filter media, a motor driveably connected to the take-up roll, and a control system for energizing the motor and thereby advancing the filter media from the supply roll to the take-up roll. Each of these components is supported by the filter frame. As a result, the entire furnace filter assembly is supported by the filter frame which is in turn removably installed on and supported by the furnace itself. Accordingly, the entire furnace filter assembly can be installed without the need for major modification of the existing furnace as it is required by the previously discussed reference to Strong and with less time and effort then is required to install the system of Najm.
Furthermore, the provisions on the filter frame for mounting each of the foregoing components are adaptable to provide a variety of mounting arrangements. For example, the supply roll may be mounted on one end of the filter frame with the take-up roll being mounted on the opposite end, and the filter media making only one pass across the filter frame. Alternatively, the furnace filter assembly may be entirely installed and accessed from one side of the furnace, in which case both the supply roll and the take-up roll are mounted on the same end of the filter frame, with the filter media extending from the supply roll across the filter, frame to the opposite end and then returning across the filter frame to the take-up roll. In either case, the installation can be quickly and easily accomplished using common tools, and without major modifications to the furnace or duct work. Additionally, as will become apparent from the discussion hereinafter, the furnace filter assembly may provide three or more areas on one end of the filter frame for mounting the supply roll and the take-up roll. These two components will only utilize two of the three or more mounting areas. As a result, a determination can be made prior to installation as to which two mounting areas will be used, and the remaining mounting area or areas can be cut off or otherwise removed from the assembly. The ability to remove the unused mounting areas provides increased flexibility during installation of the furnace filter assembly onto an existing furnace or duct work, particularly in situations where there is limited clearance around the furnace or duct work. This provides increased versatility for mounting the furnace filter assembly relative to earlier devices.
It is accordingly an outstanding object of the present invention to provide a furnace filter assembly for installation on an existing furnace, the furnace filter assembly comprising a filter frame removably mountable on a furnace and carrying supply and take-up supports for a continuous length of filter media stored on a supply roll for extending through the filter frame to a take-up roll onto which the filter media can be advanced to periodically replace contaminated filter media with clean filter media.
Another object is the provision of a furnace filter assembly of the foregoing character in which all of the component parts are supported by a filter frame so that the furnace filter assembly can be installed on an existing furnace with little or no modifications to the furnace or its attendant duct work.
Still another object is the provision of a furnace filter assembly of the foregoing character which is adapted to be installed in any one of a variety of configurations to accommodate space or access limitations with respect to an existing furnace and its attendant duct work.
Still another object is the provision of a furnace filter assembly of the foregoing character which can be provided in the form of a kit that is easily assembled and requires only a minimal number of common tools for the assembly and installation thereof.
A further object is the provision of a furnace filter assembly of the foregoing nature which is comprised of a minimum number of parts and is structurally simple, thereby promoting the economic production and ease of installation of the furnace filter assembly.